A new paper details the measures conservationists have taken to revive one of the Caribbean’s largest seabird colonies on Desecheo National Wildlife Refuge, Puerto Rico—a steppingstone for regional and global conservation goals.

FOR IMMEDIATE RELEASED: April 15, 2021

Media contact: Claudio Uribe, Island Conservation - claudio.uribe@islandconservation.org, +1 831-316-4047
Resources: Interviews, research paper, and multi-media assets.

For three breeding seasons, decoy seabirds have perched on the rocky outcrops of Desecheo Island, Puerto Rico, surrounded by mirrors and enveloped by blaring mating calls that play on repeat from a nearby loudspeaker. All this commotion has been orchestrated to tell three seabirds species that it is once again safe to nest and hopefully attract young, breeding-age birds to the Island.

In a new paper published in the British Ecological Society journal of Ecological Solutions and Evidence, scientists from Island Conservation, The Nature Conservancy, U.S. Fish and Wildlife Service, and Effective Environmental Restoration detail the tactics, results, and conservation potential that social attraction can have for the future of seabirds within the Caribbean region and globally.

We are forging a new path for seabird conservation by using complementary techniques to lure once abundant species back Desecheo. This the first active social attraction project in the Caribbean to combine these tools and stands to inform restoration on nearby islands, securing a future for some of our most threatened birds,” explains Jose Luis Herrera-Giraldo, lead author and project manager at Island Conservation.

Desecheo Revived

Seabirds were once so abundant on Desecheo that early western explorers (circa 1878) described strange black clouds above the Island; upon closer inspection, they discovered tens of thousands of seabirds blackening the sky. Within a century, the combination of US military use as a bombing range and predation by a slew of invasive species drove entire seabird populations away from the Island while other species dwindled until only a few individuals remained. Desecheo Island was designated as a National Wildlife Refuge in 1976 to protect and restore the island’s habitat. In 2015, Island Conservation and US Fish and Wildlife Service successfully rid the Desecheo NWR of invasive mammals. The native ecosystem quickly rebounded, but seabirds had been unable to securely nest on the Island for so long that breeding-age individuals might not immediately return, notes TNC scientist, Dr. Nick Holmes:

For example, if I sell my home, my kids will have a memory of living there and could return to that house. But, their kids – who never lived in that home – wouldn’t have that memory. Seabirds by nature are very colonial and attracted to calls of their own species – so perhaps we can kickstart breeding back on Desecheo by mimicking these behaviors. ”

Using a combination of decoy seabirds, mirrors, and looped recordings of mating calls, the team hopes to lure Bridled Terns, Brown Noddies, and Audubon’s Shearwaters to augment or build populations on Desecheo Island. So far, the outcomes are encouraging. Multiple Bridled Tern nests have been found with eggs, and individual Audubon’s Shearwaters have been captured on camera returning on a nightly basis to roosting on top of the speakers, which is the first record of the species roosting on Desecheo. Although Brown Noddies have not been nesting or roosting, individuals have been observed exploring the decoy colony during site visits.

The Fish and Wildlife Service looks forward to continuing to work with partners to bring back seabirds to the Desecheo NWR through this social attraction project and the monitoring of the island’s biosecurity,” says Susan Silander, Project Leader for the Caribbean Islands NWR Complex.

Global Declines of Seabirds

Seabirds are considered the most threatened group of birds globally, with approximately 30% at risk of extinction and nearly half of all seabird species threatened by the presence of invasive species that predate on eggs and chicks within breeding colonies. The introduction of non-native invasive mammals to islands has had dramatic consequences to seabirds globally and is identified as a key threat to seabird colonies in the Caribbean.

These early results are promising and indicate that in the long-term, social attraction could work, but the conservation potential goes beyond Desecheo—serving as a model for other islands in Puerto Rico and the Caribbean to augment and enrich threatened seabird populations,” remarks Herrera-Giraldo.

Reviving Desecheo’s seabird population has important implications for the security and recovery of the region’s seabirds. Moreover, the understanding we glean from using social attraction techniques on Desecheo will inform island restoration efforts globally, from removing invasive species to the recovery of threatened seabird colonies. 

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About the partners

Island Conservation is the only global, not-for-profit conservation organization whose mission is to prevent extinctions by removing invasive species from islands. We work where the concentration of both biodiversity and species extinction is the greatest – islands. Removing a primary threat – introduced invasive vertebrates – is one of the most critical interventions for saving threatened plants and animals and restoring island ecosystems. Once invasive species are removed, native island species and ecosystems can recover, often with little additional intervention. To date, we have successfully restored 64 islands worldwide, benefiting 1195 populations of 487 species and subspecies. Island Conservation is headquartered in Santa Cruz, CA, with field offices in British Columbia, Chile, Ecuador, Hawai’i, New Zealand, Palau, and Puerto Rico.

Effective Environmental Restoration Inc. (EER) is a corporation organized under the laws of Puerto Rico and registered in January 2011. EER’s mission is to create projects for the sustainable management of natural resources, habitat restoration, conservation and protection of flora and fauna, and programs for environmental education. In his short career, EER has established cooperative partnerships with federal and state agencies such as the U.S. Fish & Wildlife Services (USFWS), the U.S. Department of Agriculture (USDA), the Puerto Rico Department of Natural and Environmental Resources (DNER); and non-governmental organizations such as the Puerto Rican Ornithological Society (PROS), BirdLife International, with “Island Conservation”, with the “Conservation Breeding Specialist Group” (CBSG) of IUCN, and with the “Centre for Agricultural Bioscience International” (CABI ).

The Nature Conservancy is a global conservation organization dedicated to conserving the lands and waters on which all life depends. Guided by science, we create innovative, on-the-ground solutions to our world’s toughest challenges so that nature and people can thrive together. We are tackling climate change, conserving lands, waters and oceans at an unprecedented scale, providing food and water sustainably and helping make cities more sustainable. Working in 72 countries, we use a collaborative approach that engages local communities, governments, the private sector, and other partners. To learn more, visit  www.nature.org or follow @nature_press on Twitter.

U.S. Fish and Wildlife Service’s mission is to work with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people.  The U.S. Fish and Wildlife Service manages nine National Wildlife Refuges in the Caribbean, including the Desecheo NWR. For more information on our work and the people who can make it happen, visit fws.gov. Connect with the Service on Facebook, follow our tweets, watch the YouTube Channel and download photos from Flickr.